Structure of an anti-burglar screw bolt

ABSTRACT

An improved structure of an anti-burglar screw bolt having a pad and a nut, the bolt including a bolt head and a bolt shaft, characterized in that the bolt head is hexagonal with the inner edges being arranged with equal angle and provided with sloping faces continuing from one to another, and connection region of each of the sloping faces being a blocking face having a high-low depression, the pad being flat and circular having a diameter equivalent to the largest diameter of the bolt head, the center of the pad being provided with a through hole having a hole diameter larger than that of the bolt shaft, one face of the pad being formed into a continuing sloping face corresponding to the sloping face of the individual bolt head, the other face of the pad being provided with a plurality of equally arranged sharp engaging straps, each of the strap having an upright face and a sloping face, the sloping direction of the sloping face being similar to that of the continuing sloping face of the pad, the nut being hexagonal, the inner edge of each side thereof being provided with a sloping face corresponding to the continuing sloping face, and the connection region of each sloping face being also formed into a blocking face having a high-low depression.

BACKGROUND OF THE INVENTION

[0001] (a) Technical Field of the Invention

[0002] The present invention relates to a screw bolt, and in particular, to a screw bolt which has specific sloping face to prevent unloading without using a specific tool.

[0003] (b) Description of the Prior Art

[0004]FIG. 1 shows a conventional screw nut and bolt used for locking. As illustrated, a packing ring 11 is first placed on a working piece 6 and then a bolt 1 is inserted through the packing ring 11 and the working piece to engage with two lock nuts 12 and 13. However, the lock nuts 12 and 13 will become loose if subject to vibration for a long period time. Hence, another method as shown in FIG. 2 is proposed to obviate this drawback. The screw nut 2 is provided with a through hole 21 for an iron wire 22 to pass through. The other end of the wire 22 is mounted onto other work piece. The iron wire prevents the nut 2 from dislocation. However, this conventional structure can be easily unloaded by cutting off the iron wire 22. Therefore, this conventional screw bolt/nut cannot prevent a locked object from burglary.

SUMMARY OF THE INVENTION

[0005] Accordingly, it is an aspect of the present invention to provide an improved structure of an anti-burglar screw bolt having a pad and a nut, the bolt including a bolt head and a bolt shaft, characterized in that the bolt head is hexagonal with the inner edges being arranged with equal angle and provided with sloping faces continuing from one to another such that the shallowest region of a fore notch of the sloping face is the deepest region of a subsequent notch of the sloping face, and connection region of each of the sloping face being a blocking face having a high-low depression; the pad is flat and circular having a diameter equivalent to the largest diameter of the bolt head, the center of the pad is provided with a through hole having a hole diameter larger than that of the bolt shaft, one face of the pad is formed into a continuing sloping face corresponding to the sloping face of the individual bolt head such that the thinnest region of the fore sloping face is the thickest region of the subsequent sloping face and the individual connecting region is formed into a holding face having a high-low depression, and the other face of the pad is provided with a plurality of equally arranged sharp engaging straps, each of the strap has an upright face and a sloping face and the sloping direction of the sloping face is similar to that of the continuing sloping face of the pad; and the nut is hexagonal and the inner edge of each side thereof is provided with a sloping face corresponding to the continuing sloping face, the connection region of each sloping face is also formed into a blocking face having a high-low depression.

[0006] The foregoing object and summary provide only a brief introduction to the present invention. To fully appreciate these and other objects of the present invention as well as the invention itself, all of which will become apparent to those skilled in the art, the following detailed description of the invention and the claims should be read in conjunction with the accompanying drawings. Throughout the specification and drawings identical reference numerals refer to identical or similar parts.

[0007] Many other advantages and features of the present invention will become manifest to those versed in the art upon making reference to the detailed description and the accompanying sheets of drawings in which a preferred structural embodiment incorporating the principles of the present invention is shown by way of illustrative example.

BRIEF DESCRIPTION OF THE DRAWINGS

[0008]FIG. 1 is a schematic view showing a conventional screw bolt.

[0009]FIG. 2 is a schematic view showing another conventional screw bolt.

[0010]FIG. 3 is a perspective exploded view in accordance with the present invention.

[0011]FIG. 4 is a preferred embodiment of a sharp engaging strap in accordance with the present invention.

[0012]FIG. 5 is another preferred embodiment of a pad in accordance with the present invention.

[0013]FIG. 5A is a side view of FIG. 5.

[0014]FIG. 6 is a sectional view of the present invention.

[0015]FIG. 6A is an enlarged view of a portion of FIG. 6.

[0016]FIG. 7 illustrates the unloading of the screw bolt of the present invention using a specific tool.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0017] The following descriptions are of exemplary embodiments only, and are not intended to limit the scope, applicability or configuration of the invention in any way. Rather, the following description provides a convenient illustration for implementing exemplary embodiments of the invention. Various changes to the described embodiments may be made in the function and arrangement of the elements described without departing from the scope of the invention as set forth in the appended claims.

[0018] Referring to FIGS. 3, 6 and 6A, there is shown an improved structure of an anti-burglar screw bolt 3 having a pad 4 and a nut 5, the bolt 3 including a bolt head 31 and a bolt shaft 32, characterized in that the bolt head 31 is hexagonal with the inner edges 311 being arranged with equal angle and provided with sloping faces 312 continuing from one to another such that the shallowest region of a fore notch of the sloping face is the deepest region of a subsequent notch of the sloping face 312, the connection region of each of the sloping face being a blocking face 313 having a high-low depression, the pad 4 is flat and circular having a diameter equivalent to the largest diameter of the bolt head 31, the center of the pad 4 is provided with a through hole 41 having a hole diameter larger than that of the bolt shaft 32, one face of the pad 4 is formed into a continuing sloping face corresponding to the sloping face of the individual bolt head 31 such that the thinnest region of the fore sloping face is the thickest region of the subsequent sloping face and the individual connecting region is formed into a holding face having a high-low depression, the other face of the pad 4 is provided with a plurality of equally arranged sharp engaging straps, each of the strap has an upright face and a sloping face and the sloping direction of the sloping face is similar to that of the continuing sloping face of the pad 4, and the nut 5 is hexagonal and the inner edge of each side thereof is provided with a sloping face corresponding to the continuing sloping face, the connection region of each sloping face is also formed into a blocking face 43 having a high-low depression.

[0019] To implement the structure as disclosed above, as shown in FIG. 6, the screw shaft 32 of the screw bolt 3 passes through the pad 4 and a working piece 6 in sequence, and in turn, another pad 7 being placed in a reverse position is passed through, and a screw nut 5 is used to secure the two working piece. The bolt head 31 or the blocking faces 313, 53 of the nut 5 will urge the holding face 43 of the pads 4, 7 to drive the pads 4, 7 in rotation.

[0020]FIGS. 5 and 5A illustrate another preferred embodiment of the pad in accordance with the present invention. As shown, the inner edge of the through hole 41 is raised thereby malting the continuing sloping face 42′ extend and the sharp engaging strap 44′ against the center.

[0021] The pads 4, 7 follow the direction of the sloping face 442 of the engaging strap 44 and therefore the working piece is tightened gradually such that the sharp engaging strap 44 is forced to engage with the surface of the working piece (see FIGS. 3 and 4).

[0022] If the bolt head 31 or the nut 5 is to rotate in reverse direction, due to the resisting of the continuing sloping face 42 and the sloping face 312, 5 together the resisting of the upright face 441 of the sharp engaging strap 431 with the working piece, the screw bolt will not be dislocated.

[0023] If the screw bolt is to be unloaded, a specific tool has to be used to simultaneously unload the pad 7 with the screw nut or bolt head. If the pad 4 is in a circular shape, a common tool cannot grip the pad together with the nut or the bolt head and therefore, the screw bolt prevents the bolt from unloaded. Thus, only a specific sleeve has to be used to mount with the notch 45 of the pad 4 (as shown in FIG. 7) in order to unload the pad 4 together with the nut or the bolt head.

[0024] It will be understood that each of the elements described above, or two or more together may also find a useful application in other types of methods differing from the type described above.

[0025] While certain novel features of this invention have been shown and described and are pointed out in the annexed claim, it is not intended to be limited to the details above, since it will be understood that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation can be made by those skilled in the art without departing in any way from the spirit of the present invention. 

I claim:
 1. An improved structure of an anti-burglar screw bolt having a pad and a nut, the bolt including a bolt head and a bolt shaft, wherein the bolt head is hexagonal with the inner edges being arranged with equal angle and provided with sloping faces continuing from one to another such that the shallowest region of a fore notch of the sloping face is the deepest region of a subsequent notch of the sloping face, and connection region of each of the sloping face being a blocking face having a high-low depression; the pad is flat and circular having a diameter equivalent to the largest diameter of the bolt head, the center of the pad is provided with a through hole having a hole diameter larger than that of the bolt shaft, one face of the pad is formed into a continuing sloping face corresponding to the sloping face of the individual bolt head such that the thinnest region of the fore sloping face is the thickest region of the subsequent sloping face and the individual connecting region is formed into a holding face having a high-low depression, and the other face of the pad is provided with a plurality of equally arranged sharp engaging straps, each of the strap has an upright face and a sloping face and the sloping direction of the sloping face is similar to that of the continuing sloping face of the pad; and the nut is hexagonal and the inner edge of each side thereof is provided with a sloping face corresponding to the continuing sloping face, the connection region of each sloping face is also formed into a blocking face having a high-low depression.
 2. The improved structure of an anti-burglar screw bolt of claim 1, wherein a plurality of corresponding notches are provided between the outer edge of the pad and the corresponding continuing sloping face.
 3. The improved structure of an anti-burglar screw bolt of claim 1, wherein the pad is hexagonal shape corresponding to that of the bolt head and the nut.
 4. The improved structure of an anti-burglar screw bolt of claim 1, wherein the sharp engaging strap at the bottom end of the pad is mounted in equal distance.
 5. The improved structure of an anti-burglar screw bolt of claim 1, wherein the sharp engaging strap at the bottom end of the pad is a double sided sloping face.
 6. The improved structure of an anti-burglar screw bolt of claim 1, wherein the pad causes an elevation of the inner edge section to a height taller than the pad. 